John william abrahams



(No Model.)

J. W. ABRAHAMS.

JOINT FOR SHEET METAL'TUBING.

No. 430,458. Patented June 17, 1890.

#Zrzasses. j7Z7/67ZZ07" i; W MW W a UNITED STATES PATENT OFFICE.

JOHN WVILLIAM ABRAIIAMS, OF ALLEGHENY, PENNSYLVANIA, ASSIGNOR OFONE-HALF TO JOHN T. BEALOR, OF SAME PLACE.

JOINT FOR SHEET-METAL TUBING.

SPECIFICATION forming part of Letters Patent No. 430,458, dated June 17,1890.

Application filed November 26, 1889- Serial No. 331,608. (No model.)

To all whom it may concern:

Be it known that 1, JOHN WILLIAM ABRA- HAM's, a citizen of the UnitedStates, residing at Allegheny, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inJoints for Sheet-Metal Tubing; and I do hereby declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

My invention relates to sheet-metal tubing, and has for its objectcertain improvements in the joint therefor, which will be hereinafterdescribed, and particularly pointed out in the claims.

In the accompanying drawings, which form part of this specification,Figure 1 represents a perspective of my improved joint, and Fig.

2 a cross-section of a section of tubing provided with my joint.

Reference being had to the drawings and the letters thereon, A indicatesa section of sheet-metal tubing, which maybe corrugated,

2 5 as shown, or of any preferred form, and is made from a sheet ofmetal of any desired length and width to suit the style, length, anddiameter of the tubing to be made. On one edge of the sheet is formed ashort 0 fold a, and on the opposite edge is formed a double fold,consisting of the part b, which interlocks the fold a, the part c, whichis bent back over a and b, the part (l, which is bent under the parts aand b, and the part c,

3 5 which is bent back in the opposite direction from d, thus forming adouble-folded joint. The outer fold 0 covers and protects the joint onthe outside and affords a convenient means for applying a support if itis desired to sus- 40 pend the pipe vertically, and the folds (Z and eform an expansible seam at the point f,

which allows for expansion and contraction of the tubing, and at thesame time forms a lap joint or fold on the inside of .the pipe whichprotects the main joint.

By the construction shown the edges of the sheet forming the tubing areso interlocked that they cannot be accidentally disengaged intransportation or While being handled in putting them together, whileadequate means are provided for expansion of the tubing withoutinterfering with the joint.

It is obvious that sheet-metal tubing constructed with joints of thecharacter shown and described may be used for various purposes, and I donot therefore limit my invention to tubing for any special purpose.

Having thus fully described my invention, what I claim is- 1. A jointfor sheet-metal tubing having the edges of the sheet interlocked and afold on the outside and inside of the tubing opposite to the interlockedparts, substantially as described.

2. A joint for sheet-metal tubing having the edges of the sheetinterlocked, a fold on both sides of the tubing opposite the interlocked parts, and one of said folds being expansible, substantially asand for the purpose described.

3. Ajoint for sheet-metal tubing having interlocked folds consisting ofthe parts a, b,

c, d, and e, which provide means for attaching a support on the outside,and an expansible seam on the inside of the tubing, substantially asdescribed.

In testimony whereof Iaffix my signature in presence of two witnesses.

JOHN \VILLIAM ABRAHAMS.

WVitnesses:

S. J. BRAUFF, W. H. LOCKHART.

